1. Technical Field
The present invention relates generally to communication links including, but not limited to, serial interfaces for integrated circuits.
2. Description of the Background Art
Transceivers are used to form high speed serial interface (HSSI) links between integrated circuits (ICs). The transceivers typically use differential voltage signals to transmit and receive data. One aspect of the differential voltage signal that typically needs to be set accurately is the transmitter output swing for the differential voltage signal.
A conventional technique for calibrating the transmitter output swing use a current generated by a bandgap reference and an external (off-chip) resistor. However, using external resistor requires the use of an input/output (I/O) pin. The need to use an I/O pin is undesirable as I/O pins on an IC are a limited resource.